R-value tells us how well insulation can resist heat flow
R= Resistance to heat escape.
• Attics is R-49/60
• Sidewalls R-21
• Cantilevered Floors R-38
• Transition Walls R-21
• Basement Walls R-13
• Crawlspace Walls R-21
Illinois current standards are moving closer to a 4.0 Air Exchange Rate and R-values consistent with optimal standards.
Cost difference vs r-value difference
What is the difference in cost of different insulation materials to achieve same R-Value?
✕ Fiberglass R-Value 2.9-4.2 per inch
✕ Mineral Wool R-Value 3.0-3.2 per inch\
✕ Urea formaldehyde foam insulation 5.0per inch
✕ Plastic Board R-Value 3.7-6.0 per inch
✕ Sprayed foam R-Value 3.0-7.0 per inch
✕ Vermiculite R-Value 2.1- 2.5 per inch
Illinois current standards for construction. Choosing the right materials.
From mineral wool to radiant barriers, spray foam insulation, fiberglass insulation, foam board insulation, blown in cellulose insulation or some other less common form such as sheep’s wool, denim or others, each is measured in terms of its R-Value. In Chicago, current standards are measured in R-Value ( the resistance to heat escape ) measured on a scale from 0-70 for all intended purposes of this example.
✓ Attics is R49-60
✓ Sidewalls R21
✓ Cantilevered Floors R38
✓ Transition Walls R21
✓ Basement Walls R13
✓ Crawlspace Walls R21
